Computer simulation is used to study the effect of deep electron traps (irreversible one- electron traps) on contrast in AgCl. Theoretical response curves derived by Silberstein are used to demonstrate the highest contrast possible for a given threshold for developablilty. These curves are then used as benchmarks in the simulation study. Agreement with the theoretical curves is approached as recombination decreases, assuming the concentration of deep electron traps and their trapping radii allow their electron trapping to dominate latent-image formation. Sensitometric data on emulsions with RuCl₅(NO)²⁻ as a deep electron trap show that spectral sensitizing dyes that are expected to be good hole traps reduce or eliminate the high contrast induced by the dopant. This effect is consistent with the predictions obtained from computer simulation.